Background

Jean Piaget is most well-known for his work outlining the development of cognitive functioning in children. To understand Piaget and his work, it is first important to understand the world in which he worked. Even though Piaget started his study of psychology around the year 1919, his research didn't come into popular favor until the late 1950s and early 1960s in the United States. It wasn't until this time that the American scientific climate was ready for work such as Piaget's. It was around this time that behaviorism started loosening its strangle-hold on American psychology. American popular culture started to look to psychology for answers to practical questions that could not be answered by watching rats run mazes. Gone were the days of psychology as a science purely for science's sake.

Another major development to set the stage for Piaget's ideas was that of ego psychology. Initially, Sigmund Freud described ego functions as resulting from failure to satisfy basic needs. Later, the idea of an "conflict-free ego sphere" arose suggesting that some ego functions were natural and inborn. Today, we would call these ego functions cognitive processes. This change to believe that cognitive processes are existent and in use from birth allowed Piaget's study of the cognitive processes in children to be seen as more acceptable.

The advent and proliferation of computer technology also helped set the stage for Piaget's work in the United States. From the beginning, psychological terminology was used to describe parts of computers, such as memory. Gradually the flow of terminology reversed. Brain structures and cognitive processes began being described in terms of computers. Computers evolved and were soon capable of emulating human thought processes, replacing the automata metaphor for psychological functioning with a computer metaphor.

Stages of Cognitive Development

Piaget's work started while he was working with Simon and Binet in Paris studying children's intelligence. While interviewing children, Piaget began to recognize patterns in the responses he got from children in certain age ranges. He noticed that when children of similar ages would provide an incorrect response to a question, the types of invalid logic used to generate the answer were very similar. Over time he recorded the logical errors made by the children and mapped the types of errors to four distinct age ranges. Based on this, Piaget concluded that cognitive functioning develops in stages as a child grows older.

Sensorimotor

The first stage that Piaget outlined was named the Sensorimotor stage. This stage of development begins with birth and lasts until about two years of age and is characterized by using basic sensory input and motor abilities to learn about the world. This stage is further broken down into three sub-stages. From months zero to four, children generally demonstrate primary circular reactions. This is a circular self-contained stimulus-response, such as thumb sucking. The child sucks its thumb, which feels good, and so it continues to do so. Secondary circular reactions start at around four months and continue to around the one year mark. Secondary circular reactions are similar to primary circular reactions, but extend past the baby's self into the world. An example would be pressing a button to make a light go on. This is also the point where children develop object permanence. Before this, children seem to act as if an object ceases to exist when it is no longer able to be seen. Around one year, a child will start to demonstrate tertiary circular reactions. These are basically an extension of secondary circular actions, but the child has started abstracting responses that come from similar actions. For example, a child will learn that striking a wooden object will make a "thump" sound while striking a metal object will make a "clank" sound. The abstract response of the noise becomes associated with hitting various objects.

Preoperational

The second stage of development is the Preoperational stage. This stage goes from about two years of age to about seven years. Children begin to use symbols to represent objects or ideas. One of the best examples of this is language, where words are used to represent things. Here we also start seeing creative play. Basically, children start being able to pretend and develop an imagination. Children at this stage tend to be very ego-centric. They are unable to see things from any point of view other than their own. This is demonstrated by placing a 3D object between the child and a researcher and asking the child to describe what the researcher sees. Children at this age will have much trouble in this task.

Concrete Operational

The third stage of development is the Concrete Operational stage. This stage lasts from about seven years of age until about eleven and is characterized by the ability to logically manipulate the symbols they learned in the Preoperational stage. Children at this stage start to be able to conserve objects. This means that an object is viewed as staying fundamentally the same despite changes in appearance. An example is recognizing that spreading out a pile of marbles doesn't mean that there are more marbles, just that they are more spread out.

Formal Operational

The final stage is called the Formal Operational stage and lasts from about eleven years of age and ends with death. It is argued whether or not everyone reaches this stage of development. This is the stage where people add thinking theoretically to their skill set. Concepts such as love and "shades of grey" are understood. People are able to intake information, process it, and draw conclusions.